Manual – Starflow Ultrasonic Doppler Instrument
Model 6526
Unidata Manual - 6526 Starflow User Manual Issue 17 01 2020.docx
Page 64
13.1.1
Open Channel and Natural Stream
The dimensional definition of any open channel (or stream) consists of pairs of “distance” and
“reduced level” measurement which define the profile of the channel or stream. These pairs
comprise the Channel Cross-Sectional Area.
For constructed channels, this information is easily determined from known construction
dimensions. For natural streams, you will need to make actual measurements of the stream bed.
In addition, you require two parameters, the depth range and offset.
Range
(m) Depth range of the channel. This defines the maximum depth of the channel. There
are two ranges: 2m and 5m.
Define the smallest maximum depth for the channel that is compatible with your Starflow as this
will give best results. For example - for a 2m depth range Starflow in a 900mm maximum depth
channel, choose 1 to improve accuracy.
Offset
(m) This defines the offset (reduced level) of the Starflow instrument from the reference to
the depth sensor.
Determining Distance/Reduced Level Information
Select an arbitrary reference point above the highest water level expected. This is (0,0) pair.
Measure across the channel and down to the channel bed at sufficient number of points to define
the bed profile. Adjacent points are connected by straight lines. There may be as many
Distance/RL pairs as you need.
The reference point (0,0) may be any datum standard which must be above the highest water
level.
